The impact of air pollution on non-alcoholic fatty liver disease: A global ecological analysis of incidence and mortality trends by human development index (1990-2019).

Background: Despite the growing interest in the relationship between air pollution exposure and non-alcoholic fatty liver disease (NAFLD), no ecological study has investigated this association. This study aims to bridge this gap by examining the relationship between air pollution exposure and NAFLD burden, with a focus on the role of the Human Development Index (HDI) of countries from 1990 to 2019. Methods: We gathered data on NAFLD incidence and mortality from the Global Burden of Disease (GBD) study 2019, as well as air pollution exposure data obtained from the World Bank database. A mixed-effects regression model was employed to examine the associations, adjusting for potential confounders. A total of 189 countries were included in the analysis. Results: The global incidence rate of NAFLD was 559.95 per 100,000 people, with a mortality rate of 1.93 per 100,000. Countries with greater exposure to NO2, ozone, and PM2.5 had significantly higher NAFLD incidence (Regression Estimate per 1 SD increase (RESD) in NO2[SE] = 8.82[1.15], P-value < 0.001; RESD ozone[SE] = 17.97[1.37], P-value < 0.001; RESD PM2.5[SE] = 35.09[2.57], P-value < 0.001) and lower death rates (RESD NO2[SE] =-0.14[0.01], P-value < 0.001; RESD ozone[SE] =-0.22[0.02], P-value < 0.001; RESD PM2.5[SE] =-0.20[0.03], P-value < 0.001), particularly in countries with higher HDI. However, low-HDI countries exhibited no significant relationship between air pollution and NAFLD incidence while showing a significant positive correlation between pollutant exposure and NAFLD mortality. Conclusion: While air pollution is linked to higher NAFLD incidence globally, its relationship with mortality varies, particularly in low-HDI countries. These results suggest a need for region-specific approaches, considering the ecological context. Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-025-01751-0.